Antenna unit



May 31, 1938. s. w. CARTER ANTENNA UNI T Filed Jan. 8, 1936 INVENTOR.

ATTORNEY BY'cR. 5.-@

Patented May 31, 1938 UNITED STATES PATENT OFFICE 9 Claims.

My invention relates to the art of radio communication, and inparticular to a device particularly adapted t0 form a part of the wavecollecting or pick-up system for collecting the incident radiant energy,and the leads therefrom to the receiving set, for controlling thecharacteristics` of the received signal.

The ordinary type of pick-up device or antenna, picks up waves of allfrequencies and characteristics without discrimination, and does notexclude those waves which have undesirable characteristics.

It is an object of my invention to provide a unit to be employed in theWave-pick-up apparatus of a radio receiving station which will selectand pass toy the receiving set proper, Waves which have desiredcharacteristics, and to exclude Waves of other characteristics.

Another object of my invention is to provide a device which may beconnected in series in the lead-in of an ordinary type of antenna, andwill select desired Waves.

A further object of my invention is to provide a device which is adaptedto be used by itself as the wave collector, Without a separate antennaof usual type.

A still further object of my invention is to provide a device in whichcollected radiant energy traverses in series a path through a liquid andthrough a solid vitreous medium.

Still a further object of my invention is to provide an antenna unitwhich comprises a plurality of individual elements having external plateelectrodes and being connected in series in the antenna circuit byinterconnections which are in capacity relation to said electrodes.

Another object of my invention is to provide a device which is simple inconstruction and easily installed, and is adapted for quantityproduction at a low price.

With these and other objects in view which will be apparent from thefollowing, my invention consists in the apparatus and method as setforth in this specification and in the drawing which forms a partthereof. In the drawing:

Figure 1 shows a horizontal sectional view of an individual selectingelement of my antenna unit, with its central rod and external peripheralelectrode, and actuating liquid in place, taken on the line I-I ofFigure 2,

Figure 2 is a vertical sectional view of the selecting element of Figure1,

Figure 3 is a vertical sectional view of another form of individualselecting unit similar to that of Figures 1 and 2, but also containingfinely (Cl. Z50-20) divided metal as an additional activating element,

Figure 4 shows in plan View a unit comprising four of my individualselecting elements arranged in relatively closely spaced relation and 5interconnected in series by leads in' capacity relation to the externalelectrodes of the elements,

Figure 5 is a vertical View partly in section taken on the line 5-5 ofFigure 4 and looking 10 in the direction of the arrows; and

Figure 6 is a circuit diagram showing schematically the selectingelements and their interconnections, and their connection to' anordinary antenna and radio receiving set. ari

Incoming radio waves often have frequency components which areundesirable and which produce sounds of undesired characteristics in theloud speaker of the receiving set to which they are connected. One typeof such compo- 29 nent is the so-called strays or atmospherics which areelectrical disturbances sometimes of high decrement and covering a widefrequency band, but which in some cases are limited to a comparativelynarrow part of the frequency spec- Q, trum. This type of component isnot present in the wave emitted by the transmitting broadcast station,but is picked up during the transmission of the wave through space, andis parasitical. My device is particularly adapted to reduce the 30 eiectof such disturbances which occupy a particular range of the frequencyspectrum. Interiering electrical disturbances from nearby electricalapparatus also often occupy a particular part of the frequency spectrumand can be similarly controlled by my invention. Harmonics or otherdistortions of the wave form emitted by the transmitting radiobroadcasting station may also introduce undesired characteristics in thereceived signal, and are controllable by my invention.

I have found that by causing the radio-frequency current picked up totraverse a selecting element comprising a bottle or vessel `containingan acidulated or alkaline liquid, components of 'l5 undesiredcharacteristics are reduced.

The selecting element which I provide is conveniently a glass bottlehaving as one electrode a central metal rod immersed in the acidulatedor alkaline liquid, and as the other electrode a piece of metal foilwrapped around the outside of the bottle.

A plurality of such selecting elements may be mounted in juxtapositionand connected in series by interconnecting leads which are in capacityrelation to the several metal foil electrodes, thereby constituting anelectrical system of selective frequency characteristics.

I find that the employment of the antenna unit which I describe willunder the radio receiving conditions ordinarily met in practice, producein the loud speaker of the radio receiving set connected, an improvedand clarified tone output as compared with the sound produced undersimilar conditions without my device.

Referring to the drawing in detail, in Figures l and 2, I is a glassbottle or vial o1* vessel conveniently shaped as here shownsubstantially square. This bottle is of conventional form with a closedbottom and sloping top, and on its top surface provided with a shoulderor neck and an opening lipped to receive a tight-fitting cork 2 which isconveniently rubber. Bottles which are round or of other shape can alsobe used. I

` find that a one-ounce bottle is a convenient size for the purpose inview, but bottles as small as a quarter ounce, and as large as two-ounceand larger have also been found satisfactory. The bottle I is filledsubstantially full with an acidulated or alkalinenliquid 3 hereafterdescribed.

The rubber cork 2 is centrally pierced to receive a copper or othermetal rod 4 part of which is outside of the bottle and cork, and whichextends downwards through the cork well into the bottle and reaches intoliquid 3. Metal rod il is provided with a binding post 5. Rubber cork 2lnay be retained in position by a screw cap 2a fitting onto the neck ofthe bottle.

Wrapped around a substantial part of the vertical external surface ofbottle I is a piece of metal foil 6 which is held in place by twine orother suitable material wrapped around. A connecting wire 23 isconductively attached to foil 5 by soldering or otherwise.

In Figure 3, the bottle and its electrodes are substantially the same asshown in Figure 2, but in the bottom of the bottle there is a layer 8 offine copper or other metal lings, into which layer the lower end of rod4 may project. I find that for some purposes the liquid is maintained ina condition to attain the desired result more satisfactorily by thuskeeping a layer of such metal filings in the bottom of the bottle. Suchlayer of filings may be as thick as one-third of the height of thebottle, but layers of less thickness may also be employedsatisfactorily.

The liquid 3 with which the bottle I is filled, is usually an acidulatedliquid which may have different compositions which will produce thedesired result. However, I nd that for best results, the liquidadvantageously is composed by mixing three parts of water and two partsalcohol, and to one pint of such mixture of water and alcohol adding oneounce of sulphuric acid. This makes a fluid composed approximately often parts water, six parts alcohol, and one part sulphuric acid. Aliquid composed of only water and sulphuric acid in approximately theproportions of sixteen parts to one will also operate, but is not assatisfactory as the liquid containing the alcohol. 'I'he alcohol used ispreferably a low primary alcohol such as ethyl or methyl alcohol. I havealso found that the use in the bottle of certain alkaline liquids suchas sodium hydroxide or aluminum hydroxide in water, produces goodresults. If these alkaline liquids are used it may be preferable toplace a thin layer of a suitable oil on top of the alkaline liquid, andto pre-condition the copper rod to minimize its corrosion by the liquid,as is known in the alkaline primary battery art.

The rubber cork 2 should be tightly fitted in the bottle lip and shouldtightly grip the metal rod Il passing therethrough to form asubstantially hermetic seal, but if necessary a sealing compound may beapplied around the edges of cork 2 to insure a hermetic seal. Because ofthis tight seal, a space of about one-tenth the height of the bottleshould be left above the liquid to allow for expansion. The copper rod 4is ad- Vantageously about one-eighth inch in diameter but may be ofother size such as one-fourth inch in diameter. While I have in mostinstances employed a copper rod, other metals may also be employed forthis purpose.

The metal foil 6 wrapped around the bottle has been found to beadvantageously aluminum foil, but I have also employed copper foil andother metal foils with good results. I have also employed a closelywound single-layer winding of copper wire around the outside of thebottle instead of the metal foil, which will operate, but which I do notconsider produces as good results as the metal foil. One electrode, rodil or foil 8, is connected to the antenna, and the other electrode tothe antenna post of an ordinary receiving set. I usually prefer toconnect the antenna to the foil electrode.

A plurality of the individual selecting elements or bottles of Figuresl-3 may be employed together to produce a result which in general isbetter than that produced with a single bottle. The individual elementsmay be connected in series, or in some cases in parallel, or inseriesparallel. Figure 4 shows such an arrangement of four selectingelements connected in series. Other numbers of elements may be connectedin series, and as stated, types of connection other than the seriesconnection may also be employed. I have, for instance, satisfactorilyemployed two and three elements in series.

In Figure 4, the individual elements Ill, II, I2, I3 are provided withexternal foil electrodes Iii, I5, I5, Il, and with center rod electrodesI8, I9, 25, 2|. The four bottle elements are placed in a box 22 of sizesuitable to hold the four bottles fairly snugly but with a relativelysmall space between adjacent bottles and between each bottle and theadjacent side of the box. The showing of Figure 4 is schematic, inpractice the bottles will be fitted somewhat closer together and withrelation to the sides of the box than is shown.. The box confines thebottles relatively closely together. The bottles I usually employ areabout 31/2 inches high and are spaced about one-half inch apart. Anysuitable type of frame surrounding the bottles will also serve. Theoutside foil electrode III of element I is preferably connected by lead23 to the input lead of the ordinary type of antenna if one is employed.Center electrode I8 of element I Il is connected by interconnecting lead2li to outside foil electrode I5 of element II. Center electrode I9 ofelement II .is connected by interconnecting lead 25 to outer foilelectrode I6 of element I2. Center electrode 2l of element I2 isconnected b-y interconnecting lead 26 to outer foil electrode II ofelement I3. Center electrode 2i of element I3 is connected by lead 2l tothe antenna binding post of any usual type of radio receiving set. Ingeneral, in making the series connection, a center electrode of oneelement is connected to an outer foil electrode of the next element.

While I have found it preferable to connect the ordinary antenna, ifused, to the outer foil electrode of the first element, and to connectthe center electrode of the last element to the antenna post of thereceiving set, I also nd that it is possible to connect the antenna tothe center electrode of the first element and to connect the outer foilelectrode of the last element to the receiving set. In general it may besaid that a tone of better quality will be delivered under ordinaryoperating conditions by connecting the antenna to the outer foilelectrode of the iirst element, and the receiving set to the centerelectrode of the last element. However, I also find that a sound ofgreater volume is usually produced if the antenna is connected to thecenter electrode of the first .element and the receiving set isconnected to the outer foil electrode of the last element; while thislatter arrangement does not produce as good a quality of sound if thereceiving conditions are bad, with good receiving conditions it may bequite satisfactory.

Figure 6 is a schematic circuit diagram of the arrangement of fourelements of Figure 4, as connected to an antenna and receiving set. 28is an ordinary type of antenna connected to the blade 30 of asingle-point double-throw switch. One point 32 of this switch isconnected by lead 23 to outer foil electrode I4 of the first element I0,and the center electrode 2| of the last element I3 is connected by lead21 to antenna binding post 36 of receiving set 35, which constitutessubstantially the arrangement shown in Figure 4 when the blade of switch29 is in the right position and engages point 32.

I also find that in certain kinds of conditions of reception, it isdesirable to be able to use only one element in the circuit for a time,and still be able to throw all four elements into circuit on an instantsnotice. The switch 29 makes this possible. By throwing the blade ofswitch 29 to its left position (Figure 6) so that it engages point 3|,elements II), II, I2, are cut out of the circuit, and antenna 28 isconnected directly through lead 34 .to outer foil electrode I'I ofelement I3, so that only element I3 is in the circuit.

As shown in Figures 4 and 6, one or more of the interconnecting leads24, 25, 26, may be formed of insulated coiled wire, which mayadvantageously be helically coiled. In this way a length of say ve feetof wire may be coiled into a length of about nine inches, in one ofthese interconnecting leads. A box containing several elementsinterconnected by one or more such coiled interconnections contains itsown effective antenna, and it is not necessary to attach a conventionaltype of antenna as 28 to the first elcment, if it is not convenient todo so. My invention therefore constitutes a very convenient, compact anduseful form,of receiving antenna, entirely apart from its wave selectiveproperties. For four one-ounce bottles such as I have described whichare about 31/2 inches high, the box 22 need only be about four incheshigh, and about the same size in the other dimensions, forming a verycompact unit. In Figure 6, if only a single element is to be connected,the single lead 34 may also be formed of coiled wire.

Also, as shown in Figures 4 and 6, the inter-- connecting leads 24, 25,26, are positioned between the several bottles or elements, or between abottle and the side of box 22, relatively close .to the outer foilelectrodes of the several elements, so as to be in electricalcapacitative relation to the respective foil electrodes. A longer one ofsuch interconnecting leads, such as 26,

may be doubled reentrantly upon itself as shown in Figure 6, whichmaterially increases its capacity effect with relation to the foilelectrodes of both adjacent bottles.

In the arrangement of a number of elements as shown in Figures 4 and 6,I have usually obtained best results by employing for the rst elementnearest the antenna the type of element shown in Figure 3 having a layerof copper filings in the bottom of the bottle, and using the form ofFigure 2 without such filings for the other elements. Also I haveobtained good results by using the two elements nearest the antenna withsuch copper lings, and the other elements without filings. While thedetermination of whether to use the type of bottle containing copperfilings seems to depend on the particular reception conditions to bemet, in general, the element with copper iilings should be nearest theantenna.

My invention may be applied to receive both long, short, and ultra-shortWaves. The determination of what particular form and size of my antennaunit is most suitable to meet a given condition depends on theparticular receiving conditions which exist. In general, it may be saidthat if the wave characteristics which it is desired to controlcorrespond generally to long waves, an antenna unit of larger dimensionswill be used than if the wave characteristics to be controlledcorrespond to short Waves. A number of different boxes of my antennaunits may be provided for a given receiving set, such boxes being ofdifferent sizes and containing bottles of different sizes with outerelectrodes of corresponding sizes, and having interconnecting leads ofdifferent lengths. When a troublesome condition of reception is met, oneof such boxes after another may be quickly connected in turn to thereceiving set, and the one most suited to the existing conditionselected.

In operation, with a single element, the antenna is connected to oneelectrode of element I, as to foil electrode 6 by lead 23, and the otherelectrode of element I, as rod 4, is connected to the antenna post ofthe receiving set. A bottle without the copper filings may be firsttried. A bottle with copper filings may then be substituted, and thebottle used which produces the best result. Preferably, however, Iemploy a plurality of bottles connected in series, as has beendescribed. With a plurality of bottles, as has been described,preferably the one nearest the antenna contains some copper filings. Thecoiled interconnecting leads between the adjacent bottles are positionedin capacitative relation to the foil electrodes of the nearby bottles.The ordinary antenna, if used, is connected to one electrode of the rstbottle as to foil elec-- trode I4 of bottle I0, and the oppositeelectrode of the last bottle, as rod 2| of bottle I3, is connected tothe antenna post of the receiving set. If a plurality of boxes isavailable containing several such bottles of different sizes andcharacteristics, one box after another may be tried to get the box whichgives best results. For some kinds of reception conditions, it may befound that bottles containing the alkaline liquids mentioned, givebetter results than bottles containing the acidulated liquids.

I nd that the signal received on a receiving set when using one or moreof my antenna selecting elements in the antenna circuit, is materiallyimproved in quality and clarity as compared with the signal when myelements are not so used, particularly if bad receiving conditionsexist. I

believe that the liquid which I employ probably forms a microscopicallythin gas iilm at points around the center electrode, which gives acapacity effect at this point to a certain extent and a capacity path atthis point, although the liquid may have conductive relation with thecenter electrode at other points. The Waves also have a liquid paththrough the acidulated or alkaline liquid, and a glass path through theglass side of the bottle. My device constitutes a selective impedanceelement, delivering a Wave of diilerent character from that received. Ibelieve that the helical windings forming the interconnecting leads,which are adjacent and in capacity relation to the outer foilelectrodes, form With the bottle elements an electrical net Work ofinductances an-d capacities which is able to control the frequency andother characteristics of the Waves transmitted to the receiving set. Ibelieve that this is the most probable explanation of the Way in whichmy invention produces the useful results which I obtain. However, I donot wish to rely upon .this as the only possible explanation of thescientic principles of the operation of my invention, since furtherinvestigation may show that my results are obtained by virtue of someother scientic principle.

lViy invention has been found to produce very satisfactory results, issimple to construct and apply, and may be employed by persons having notechnical familiarity with radio communication.

Having now particularly described my invention and in what manner thesame is to be performed, what I claim as my invention for which I desireto secure Letters Patent of the United States is:

l. In a receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing an acidulated liquid,a plurality of conducting metallic sheets respectively Wrappedperipherally around the exteriors of said vessels, a plurality ofmetallic rod members respectively extending into the interior of saidvessels from the exterior thereof and being in contact with said liquidtherein, a plurality of interconnecting leads respectively connectedfrom said rod member of one of said vessels to said metallic sheet ofanother of said vessels for connecting said vessels in series, at leastone of said interconnecting leads comprising a relatively long andrelatively closely wound conductor positioned adjacent said metallicsheets of a plurality of said vessels, and frame retaining meanssurrounding said vessels and holding the same relatively closelyadjacent each other and With said interconnecting lead adjacent saidmetallic sheets being in cap-acitative relation thereto.

2. The subject matter of claim l, said acidulated liquid consistingapproximately of ten parts water, six parts of a low primary alcohol,and one part sulphuric acid.

3. In a receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing an acidulated liquid,

a plurality of conducting metallic sheets respectively vvrappedperipherally around the exteriors of said vessels, a plurality ofmetallic rod members respectively extending into the interior of saidvessels from the exterior thereof and being in contact with said liquidtherein, a plurality of interconnecting leads respectively connectedfrom said rod member of one of said vessels to said metallic sheet ofanother of said vessels for connecting said vessels in series, at leastone of said interconnecting leads comprising a relatively long andrelatively closely wound conductor positioned adjacent at least one ofsaid metallic sheets of one of said vessels, and frame retaining meanssurrounding said vessels and holding the same relatively closelyadjacent each other and with said interconnecting lead adjacent saidmetallic sheet being in capacitative relation thereto.

4. In a receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing a liquid consistingof sodium hydroxide and Water, a plurality of conducting metallic sheetsrespectively Wrapped peripherally around the exteriors of said vessels,a plurality of metallic rod members respectively extending into theinterior of said vessels from the exterior thereof and being in contactwith said liquid therein, a plurality of interconnecting leadsrespectively connected from said rod member ol.

one of said vessels to said metallic sheet of another of said vesselsfor connecting said vessels in series, at least one of saidinterconnecting leads comprising a relatively long and relativelyclosely wound conductor positioned adjacent said metallic sheets of aplurality of said vessels, and frame retaining means surrounding saidvessels and holding the same relatively closely adjacent each other andwith said interconnecting lead adjacent said metallic sheets being incapacitative relation thereto.

5. In a receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing a liquid consistingof aluminum hydroxide and Water, a plurality of conducting metallicsheets respectively Wrapped peripherally around the exteriors of saidvessels, a plurality of metallic rod members respectively extending intothe interior of said vessels from the exterior thereof and being incontact with said liquid therein, a plurality of interconnecting leadsrespectively connected from said rod member of one of said vessels tosaid metallic sheet of another of said vessels for connecting saidvessels in series, at least one of said interconnecting lea-dscomprising a relatively long and relatively closely Wound conductorpositioned adjacent said metallic sheets of a plurality of said vessels,and frame retaining means surrounding said vessels and holding the samerelatively closely adjacent each other and with said interconnectinglead adjacent said metallic sheets being in capacitative relationthereto.

6. In a. receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing a liquid selectedfrom the group consisting o'l acidulated liquids and alkaline liquids, aplurality of conducting metallic sheets respectively Wrappedperipherally around the exteriors of said vessels, a plurality ofrnetallic rod members respectively extending into the interior of saidvessels from the exterior thereof and being in contact with said liquidtherein, a plurality of interconnecting leads respectively connectedfrom said rod member of one of said vessels to said metallic sheet oianother oi said vessels for connecting said vessels in series, at leastone oi said interconnecting leads comprising a relatively long andrelatively closely Wound conductor positioned adjacent said metallicsheets of a plurality of said vessels, and frame retaining meanssurrounding said vessels and holding the same relatively close- 1yadjacent each other and with said interconnecting lead adjacent saidmetallic sheets being in capacitative relation thereto.

7. In a receiving antenna unit, a plurality of closed vessels formed ofelectrical insulating material and each containing a liquid selectedfrom the group consisting of acidulated liquids and alkaline liquids, aplurality of conducting metallic sheets respectively Wrappedperipherally around the exteriors of said vessels, a plurality ofmetallic rod members respectively extending into the interior of saidvessels from the exterior thereof and being in contact with said liquidtherein, a plurality of interconnecting leads respectively connectedfrom said rod member of one of said vessels to said metallic sheet ofanother of said vessels for connecting said vessels in series, at leastone of said interconnecting leads comprising a relatively long andrelatively closely wound conductor positioned adjacent at least one ofsaid metallic sheets of one of said vessels, and frame retaining meanssurrounding said vessels and holding the same relatively closelyadjacent each other and with said interconnecting lead adjacent saidmetallic sheet being in capacitative relation thereto.

8.v In a receiving antenna unit, a plurality of closed vessels formed ofvitreous electrical insulating material, each of said vessels containinga liquid selected from the group consisting of acidulated liquids andalkaline liquids, a plurality of conducting metallic sheets respectivelywrapped peripherally around the exteriors of said vessels, a pluralityof metallic rod members respectively extending into the interior of saidvessels from the exterior thereof and being in contact with said liquidtherein, a plurality of interconnecting leads respectively connectedfrom said rod member of one of said vessels to said metallic sheet ofanother of said vessels for connecting said vessels in series, at leastone of said interconnecting leads comprising a relatively long andrelatively closely wound conductor positioned adjacent at least one ofsaid metallic sheets of one of said vessels, frame retaining meanssurrounding said vessels and holding the same relatively closelyadjacent each other and with said interconnecting lead adjacent saidmetallic sheet being in capacitative relation thereto, an initial one ofsaid vessels having no interconnecting lead connected to its metallicsheet, and a terminal one of said vessels having no interconnecting leadconnected to its rod member, a receiving antenna connected to themetallic sheet of said initial vessel, and means for connecting the rodmember of said terminal vessel to the antenna input post of a radioreceiving set.

9. In a receiving antenna unit, a plurality of closed vessels formed ofvitreous electrical insulating material, each of said vessels containingan acidulated liquid, a plurality of conducting metallic sheetsrespectively wrapped peripherally around the exteriors of said vessels,a plurality of metallic rod members respectively extending into theinterior of said vessels from the exterior thereof and being in contactwith said liquid therein, a plurality of interconnecting leadsrespectively connected from said rod member of one of said vessels tosaid metallic sheet Of another of said vessels for connecting saidvessels in series, at least one of said interconnecting leads comprisinga relatively long and relatively closely Wound conductor positionedadjacent at least one of said metallic sheets of one of said vessels,and frame retaining means surrounding said vessels and holding the samerelatively closely adjacent each other and with said interconnectinglead adjacent said metallic sheet being in capacitative relationthereto.

SAMUEL W. CARTER.

